In the field of craft products numerous devices have been made to assist a user in cutting a properly shaped and precisely measured circle from a sheet media, such as craft paper. For example, a basic circle compass may be used to draw a circle on a sheet media and then the circle may be cut using an ordinary pair of scissors. However, such a method for cutting circles is entirely too imprecise as well as too slow for high level craft needs. As such, specialized circle cutting devices have been generated.
One such exemplary prior art circle cutting device is shown in RE 38,354, including a stationary ring board having a rotatable insert, mounted to the stationary ring board using ball bearings. The rotatable insert has a plurality of holes on the surface for receiving a cutting device in order to cut precisely sized circles. This reference does not disclose a radial channel for the insertion of an adjustable cutting tool.
U.S. Pat. No. 4,426,781 to Kufrin discloses a disc cutter capable of cutting two different size discs, having an outer housing and an inner rotary housing carrying the cutter blade and means to adjust the cutter blade. This reference has the disadvantage that it is limited to cutting circles of two sizes only.
U.S. Pat. No. 3,621,574 to Yanke et al. discloses a circle cutter comprising a central disc and a radially adjustable cutting arm. The circle cutter is provided with an open channel which slidably receives the cutting head. This reference does not disclose an inner rotary disc and therefore this circle cutter has the disadvantage that the relatively small radiuses cannot be cut because of the size of the base which must be relatively large to allow the compass to be manipulated.
U.S. Pat. No. 5,007,320 to Craig et al. discloses a compass having a lower surface engageable with the material, a support member rotatably supported on the base and a toolholder mounted on the support member. The support member is provided with an elongated slot and a measurement scale with the toolholder being located in the slot. To adjust the blade, the thumbscrew is loosened and the toolholder assembly slides along the slot and once the correct position is attained, the thumbscrew is tightened. This reference does not disclose an adjustment mechanism comprising a worm screw and an adjustment knob which allows for precise positioning of the blade.